Electrical relay.



G. H. NORTH, ELECTRICAL RELAY. APPLIOATION FILED NOV. 13. 1908.

972,634. 1 Patented Oct. 11, 1910.

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UNITED STATES PATENT OFFICE.

CHARLES H. NORTH, OF CLEVELAND, OHIO, ASSIGNOR TO THE NORTH ELECTRIC COM- PANY, OF CLEVELAND, OHIO, A CORPORATION OF OHIO.

ELECTRICAL RELAY.

lays, of which the following is a specification, reference being had therein to the accompanying' drawing.

' My invention relates to electrical relays, and has for its object the improvement and simplification thereof in the manner hereinafter pointed out.

In telephone and similar electrical systems, the equipments are usually built up as aggregations of small units, mounted 'in=sets of some convenient number upon strips, bars or the like and all assembled upon convenient racks or frames. In order to facilitate wiring and also to afford access to the parts for adjustment and repairs, the relays upon thesev racks are usually end-supported in rows upon mounting strips. Each relay comprises an electromagnet and armature, and contacts governed by the latter. There are certain requirements to be met, however, which have resulted in the gradual evolution of av peculiar type of relay especially adapted for telephonic installations and for the end-mounting referred to. Among these requirements are: (l) a small lateral dimension so as to save space upon the racks; (2) simplicity and certainty in contacts and connections, and in the action of the armature upon the contacts; (3) a good magnetic circuit, with a small air gap, so as to insure quickness; (a) permanent wiring connections accessible from the rear of the rack, with contact ends or points and all adjustments accessible from the front; (5) capacity for several sets ofmake or break or make and break contacts. 'One type of. relay hithertoproduced to meet these requirements has a long core with a winding-upon it, a return bar connected'at one end to the core and having its long limb extending parallel to the same along one side of the winding, an armature, 'anda number of sets of elongated German silver springs with platinum points, secured on the return bar. and actuated by the armature. In certain points this type of-relay does not fully meet the stated requirements. For" example, if a bell crank armature is employed, it has a short upper arm or lifting Specification-of Letters Patent. Application filed November 13,1968. Serial No. 462,427.

member, so that there is no multiplication of motion between the armature end and the lifting end. Inasmuch as the springs extend forwardly from the lifting end, the latter cannot be lengthened without either engaging them at a point removed from their ends, where they are stiffer, or shortening them, and thereby losing resilience. An.- other point is that in all relays of this type within my knowledge, the magnet core is secured to the rear end or angle of the return bar,,'extending out therefrom and threaded for the purpose of securing the entire struc- Patented Oct; 11, 1910.

ture upon the rack. This prohibits any adjustment of the air gap by adjusting the core, because to do so would necessitate takmg down the entire structure.

It isthe object of the invention to supply.

these and other deficiencies, and to provlde certain new features by which the efficiency of the relay is greatly increased, and it is rendered particularly suitable for use in automatic and semiautomatic telephone systems, where the response to and repetition of working impulses is required to be very quick and sharp.

To attain my object I form a magnetic frame piece of a return barhwith an extended longitudinal member, and bend both ends over at right angles, one serving forattachment to the mounting strip on the rack, and the other to support the magnet core and its winding. I employ a bell crank armature.

of hanging this armature on the extremity of the return bar, I make an opening in the latter and drop the Ve'rticalmember through this opening. The contact springs are I mounted on the rack end of the return bar,

and extend forwardly over the armature, to

the forward end thereof, by which they are operated. It will thus be observed that I have contact points, the armature end,- and the magnet core all accessible for purposes of inspcctiomadjustment and're airs. The

end of the core has a detachab e threaded extension provided with a locknut so that not only can the gap be adjusted, but the electromagnet may beremoved bodily without taking downt-he relay from the rack or disturbing the permanent wiring. thereof.

lay embodying my im rovements.

core and spool is independent of every other dimension or part, and may be varied at, will while still using standard partsother w1se.. My invention is illustrated in the accom-' panying drawings in which p Figure 1 is a side view of a complete re- Fig 2 is a frontend view 0 the same. Figs. 3 and 4 are plan views, the former with all springs in place and the latter with all springs removed. Fig. 5 shows a modified arrangementof the return bar, with a separate mounting angle carrying the contact springs, this permitting removal of the magnet structure as a wholewithout detaching the springs, and also somewhat simplifying the manufacture of the parts; Fig, 6 is-a detail of the insulating bridge. Fig-7 is a perspective view of the naked return bar and armature.

, Referring to the drawings, .1. indicates the return'bar, having its ends 2 and 3 both bent over at right angles to its body, the end 2 being perforated and tapped at 4 for. the reception ofmachine screws by which it may be secured to the supporting strip on the rack, and the end 3 being centrally perfo rated and tapped at'5 for the reception of thethreaded end of the c'ore 6. Suitable adjusting and locking means 7 are provided for the core, which may be of any desired and suitable type. In the topvof the return bar 1 and near the rear end thereof I produce an opening 8, the front edge of which constitutes a fulcrum for the armature. This armature is marked 9, and is provided with an integral extension arm or lever 10 bent at a slightlyobtuse angle, so that when the arm lies flat upon the top of the return bar as shown in Figs. 6 and 7, the armature will be slightly offset from the end of the mag net core 6. The size of the air gap is of course adjustable by means of the mechanism 7, and the relative distances from the knife edge fulcrum to the center of the magnet core and to the working end of the lever 10 are such that only a very small gap is required for a good working movement of the lever end. vAt its forward end the lever 10 is provided with lateral-extensions 11 and 12, and upon this end I mount a row of studs l3, l4 and 15, for actuating the contact springs. These studs should preferably be of such a length that when the armature is retracted they will not quite touch the operating springs, this being especially the case when the springs are in sets of three for make and break. The contact springs springs in the same sets as the contact may be in one,-tw0, three or more sets. l

. of three contact springs as best shown in Fig. 1, and each of the outside sets has in addition a stub spring 19 attached to one end (of the winding 20 on the core 6, and constituting a terminal therefor. The springs are separated by insulating slips 21, and each. set is fastened by means of screws 22 and an overlying metal washer 23 to a U- shaped mounting plate 24, Whicli is secured to the return bar preferably by screws 25 inserted from beneath. This method of mounting enables me to assemble all the springs as a unit'on the plate 24 and to at- I tach the same to and remove them from the relay at will, without disturbing the rest of the structure. The plate- 24 has an additional function, in that it covers the .opening 8 ofthe return bar, and keeps the armature u in' position. It is so proportioned that when attached to the return bar the front edge of its body (marked 26 in Fig. 4), lies parallel to the .knife edge, with just enough space for the passage of the armature lever; while its projecting members 27 and 28 lie on both sides of the lever 10. The thickness of the plate 24 is not less than the thickness of the armature lever, the springs being thus raised above the latter.

Near the forward end of the return her is mounted t bridge 29, shown in Figs. 1, 2, 3

and 6. This has an opening 30 in which the lever 10 plays, and openings 31 for the pas sage of the contact springs, one for each set.

The bridge is attached to the bar preferably by screws inserted from beneath as indic ted at 32 in Fig. 1. It serves both as a giiide and limiting stop for the armature lever and as a support and stop for the several contact springs. Thus, referring to Fig. l, the

lower spring 16 is given a downward setv which causes it to press against the lower ed e of the'opening 31, spring 16 is similar y given an upward set which springs it agamst the upper edge of the opening, and '16 is given'a downward set so that it normally rests in contact with 16 The bridge is set farenough back from the ends of the springs so that the latter may yield slightly, thus avoiding absolutely solid contacts, which would be bad practice, and necessitate diflicult adjustments where the actuating part is common to them all.

In Fig. 5 l have shown a modification in which the member 2 and the plate 24 are combined in one angle piece separate from the return bar 1. By removing the screws 25 or any equivalent fastening devices that may be employed, the parts 1, 3, 6, 7, 9, 10, 13, 14, 15 and 20 may be removed from the their connections on. the rack. An additional advantage is that a magnet and return bar of any desired length may be employed, without changing the dimensions or arrangements of the springs or their mounting plate 24, so long as the lever 10 has its studs set properly to engage the ends of the springs. If the magnet structure is made longer than that shown in Fig. 1, its extension would be in a forward direction, that is to saly toward the left in Fig. 1, the distance between the member Qand the knife edge fulcrum for the armature being preferably kept constant. WVith the construction shown in Fig.5, since the member 2 is separate, the opening 8 in the rear end of the return bar is reduced to a slot which facilitates the introduction of the armature.

Various changes may be made in details of construction in thisrelay without departing from the spirit of my invention, such for example as using two magnet spools with parallel cores forming a so-called horseshoe or double pole magnet, instead of a single magnetic element such as I have described. I believe I am the first to make a relay of this type with a bell crank armature fulcrumed at the rear instead of the front end of the magnet, so as to bring the butt of the magnet core to the front; also that I am the first to pivot or fulcrum the actuating lever at a point adjacent to the point of support of the springs, extendingit substantially parallel therewith and connecting it thereto at its end whereby a long leverage is obtained without increasing the total length of the structure beyond that required by the dimensions of the springs themselves. I shall therefore claim these features broadly, and wish it clearly under- 7 stood that I contemplate all non-essential changes or modifications which come'fairly within the scope of the invention defined in the appended claims.

Having thus described my invention wha I claim and desire to secure by Letters Patent is I 1. 'A relay comprising an electromagnet, contact springs mounted upon the magnet structure, an armature lever pivotally supported at a point adjacent the mounting of the springs, an operative connection between the free end of thelever and the springs, and an armature connected to the lever and, extending acrossan exposed pole of the electromagnet adjacent the pivotal support, whereby a small air. gap and mul tiplied motion of 'the free end of the lever are secured. I

2. In a relay, a magnetic core carrying a winding, a magnetic return bar extending parallel to the core, contact springs secured upon the return bar and extending along the same parallel with the magnet core, an armature lever pivotally mounted upon the return bar at a point adjacent to the spring mounting, and extending along the bar to a point adjacent the ends of the springs, and an operative connection between the lever and the springs.

3. In a relay, an electromagnet, a return bar therefor, contact springs thereon, an armature lever of approximately the same length as the springs, mounted on the bar so as to extend in the same direction as the springs, and an operative connection between the ends of the bar and the springs.

4. In a relay, an electromagnet, a relatively short armature adjacent an exposed pole of the magnet, contact springs, and an extended armature lever for operating the same, said springs and lever having adjacent points of support and parallel motion in operation.

5. A relay comprising an iron return bar,

a magnet core mounted upon the front end.

of the bar and extending rearwardly parallel to the same, contact springs and an armature lever mounted upon the rear end of the return bar and exten in forwardly, a winding upon the core, and an operative connection between the forward ends of the lever and springs.

6. A relay having elongated contact springs and a-correspondingly elongated operating lever therefor, mounted so as to have parallel motion, and a relatively short armature working on a small air gap, said lever and armature being so related and connected that the movement of the armature will be multiplied when'communicated to the springs.

7. A relay comprising an electromagnet structure having an adjustable core, contact springs having free adjustable tips, a bell crank armature and its lever with means thereon for actuating the springs, and a winding for the electromagnet, all of the fixed elements being secured upon one end of the'structure and all of the adjustable elements accessible at the other.

8. A relay having an electromagnetic frame or return bar, a core adjustably mounted upon one end of said bar and extending parallel therewith, contact springs and an armature mounted at the other end of said bar, a winding upon saidcore, and an actuating lever connected to the armature and extending along the bar parallel to the springs, withan actuating connection adjacent the ends thereof.

9. A relay adapted for end-support comprising an elongated return bar having both ends bent at an angle to the body, means for attaching the rear end to a support, a core adj ustably attached to the front end, and extending parallel with the body, a winding on said core, contact springs secured upon the body adjacentjto the rear end thereof and extending mun therewith. an armature mounted a jacent'to the rear end of the &

body, an actuating lever connected thereto and extending parallel to the springs, and an operative connection between said lever and springs adjacent to the front end of a the body.

1 0. relay comprising the following instrumentalities: an elongated frame or return bar having both ends bent over at substantially right angles, a core adjustably secured to the front end, and extending parallel with the bar for a portion of its length, so as to leave an open space between the rear end of the core and the rear bent end of the frame, a bell crank armature and lever extending through an opening adjacent the 4 rear end of the frame and fulcrumed on the front edge of said openin with the armature extending downwardl y into juxtaposition with the end of the core and the lever extending along the body of the frame, a mounting plate secured upon the rear end of the frame over the said opening, so as "to cover the same and prevent displacement of the armature, contact springs mounted upon but insulated from said plate, and extending forwardly along the frame parallel to the armature lever, and an insulating connection between the forward ends of thearmature lever and the springs.v

11. A relay comprising the following instrumentalities: an elongated frame or return bar having both ends bent over' atsubstantially right angles, a core adj-ustably secured to the front end, and extending parallel with the bar for a portion of its length, so as to leavean open space between the rear end of the core and the rear bent end of the i frame, a bell crank armature and lever exthe armature, contact springs mounted upon but insulated from said plate, and extend-- ing forwardly along the frame parallel to the armature lever, and an insulating connection between the forward ends of the armature lever and the springs, together with a bridge of insulating material mounted upon the frame and provided with openings for the said lever and springs, forming a guide therefor and stops for the springs.

12.- A relay having a frame or return bar, I

contact springs and an actuating lever mounted thereon, and a bridge also mounted thereon and provided with openings for the passage of the leverl and springs.

In testimony whereof I aflix my signature in presence of two witnesses.

CHARLES H. NORTH. Witnesses: I

E. H. WILLIAn'rs, H. R. WHITING- 

